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14 . 2 Effects of Electric Current on the Human Body

Electricity is a safe, clean and quiet method of transmitting energy. However,
this apparently benign source of energy when accidentally brought into contact with
conducting material, such as people, animals or metals, permits releases of energy
which may result in serious damage or loss of life. Constant awareness is necessary to
avoid and prevent danger from accidental releases of electrical energy.

The electric current that passes through the body, causes thermal, electrolytic,
biological and mechanical action.
The thermal effect of electric current causes skin burns, heating to a high
temperature of blood vessels, nerves, heart, brain and other organs that are on the
current path, and causes them serious functional disorders.
The electrolytic effect of electric current appears in the electrolysis
(decomposition) fluids, including blood.
The biological effect of electric current appears in the stimulation and
excitement of living tissues, resulting in the observed convulsive muscle contractions
that can lead to respiratory arrest, the breakdown of tissues and organs, dislocation of
limbs, spasms of the vocal cords.
The mechanical effect of electric current is evident in tissue separation and
isolation even in parts of the body.

The principal hazards associated with electricity are:
 electric shock;
 electric burns;
 electrical fires and explosions;
 static electricity
 arcing;
 portable electrical equipment;
 secondary hazards.

These hazards can be a result of:
 direct contact with exposed energized conductors or circuit parts. When
electrical current travels through our bodies, it can interfere with the normal electrical
signals between the brain and our muscles (e. g., heart may stop beating properly,
breathing may stop, or muscles may spasm);
 when the electricity arcs (jumps, or “arcs”) from an exposed energized
conductor or circuit part (e. g., overhead power lines) through a gas (such as air) to a
person who is grounded (that would provide an alternative route to the ground for the
electrical current).

 Electric shock and burns

Electric shock is the convulsive reaction by the human body to the flow of
electric current through it. This sense of shock is accompanied by pain and, in more

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